These movies are an informed interpretation of the scientific
literature on rat vision, within the limits of current
technology.

The biggest difference between the movies and actual rat vision is
that rats have a much wider field of vision than we do. Therefore,
rats see the world going by above and on either side of them as well
as in front. But computer screens are flat, and humans have
forward-facing eyes, so it would be very difficult to portray this on
a flat screen. Any portrayal of panoramic vision on a flat surface
would be greatly distorted. The best way to experience panoramic rat
vision might be in an IMAX theater, which projects an enormously
expanded field of view.

Regarding color, rats can distinguish ultraviolets, blues and
greens. However, these color cues don't seem to be very meaningful to
them: it takes rats a long time to be trained to discriminate these
colors. In contrast, they can be trained to discriminate brightnesses
pretty quickly. I interpret this to mean that rats can sense these
colors, but these colors must be faint or the rats would use them
naturally. To represent this, I reduced the color saturation down to
a barely noticeable level.

Regarding blur, all the literature I've read agrees that rats have
poor visual acuity. A recent paper put rat vision at about 20/600. I
have 20/600 vision myself, so in the rat movie I matched the degree
of blur in the movie to what I see without my corrective lenses.

Albino rats have extremely poor vision, estimated at 20/1200. To
represent this I doubled the blur. The retinas of albino rats are
flooded with light because their irises are translucent. This
dazzling leads to gradual degeneration of the retina with exposure to
ambient light. To simulate this dazzling I increased the lightness of
the image.

Methods

To make the movie, I took a series of still photographs using a
Kodak DC240 digital camera. I advanced the camera about 1 cm between
each shot, and took a total of 148 photographs. In Photoshop, I
edited the photos to approximate the rat's vision. To approximate
red-green colorblindness, I changed the red channel to solid black,
then copied and pasted the green channel into the red channel. To
mimic the rat's faint perception of color, I reduced the color
saturation of the image down to a just noticeable level (-70%). To
mimic the rat's blurry vision, I applied a Gaussian blur (I have
20/600 vision myself, so I tried to match the amount of blur to what
I see without corrective lenses). I used a Gaussian blur of 8 pixels
(this blur looked right when the image size was subsequently reduced
by 50% for the movie). Once the images were edited, I strung them
together at 12 frames per second using a program called QuickMovie.
To simulate the albino rat's vision, I reduced the color saturation
by -80% and doubled the blur (Gaussian blur of16 pixels). I increased
the lightness by 30% to simulate the light flooding through the iris
to dazzle the retina. The "human cam" movie is made from the original
set of unmodified photographs.